[Apollo 15]

FLOWN TO THE SURFACE OF THE MOON IN THE LUNAR MODULE “FALCON.”

The fourth mission to successfully land on the lunar surface, Apollo 15 was the first to use the Lunar Roving Vehicle (LRV), a battery-powered, four-wheeled rover more affectionately known as the "Moon buggy," seen here in CDR Scott's WSS portrait. As author Earl Swift has noted, the Moon buggy was "transformative" for the Apollo program: on Dave Scott and Jim Irwin's first three drives in the LRV, they recorded over 17 miles of driving, covering more territory than all of the three previous missions combined. Thus, the buggy not only allowed the crew to cover much more ground, but they could also load it with lunar samples, carry more and diverse tools, and use far less life support than during previous missions.

Apollo 15 was also the first mission to include the Scientific Instrument Module (SIM) in bay 1 of the Service Module, which contained instruments such as lunar mapping and panoramic cameras, as well as gamma ray, X-ray, and alpha particle spectrometers, used to measure the chemical composition of lunar rocks. On August 6th, 1971, at approximately 171,000 nautical miles from Earth, Al Worden performed the first "deep space" EVA in history, in order to retrieve the film cassettes from the SIM.

Hadley Rille, close to the Apennine Mountains, was chosen, partially, for the variety of its terrain. The rough terrain made for a hard landing, but the imagery of the gentle mountains behind the astronauts seen in the increased television coverage and excellent surface photography helped to revive public interest in the Apollo program. Among the great television moments was when Dave Scott demonstrated Galileo’s theory that objects of differing mass, in this case a hammer and a feather, fall at the same rate when air resistance isn’t a factor.